Due to some unknown problems which could not be fixed with the old version, I decided to upgrade mailman to 2.1 version. This version seems to be more feature rich particularly for the administrators. During this repairing period all the messages posted were delivered yesterday early morning.
Please let me know if you are facing any recent problems. this will help us to keep mailman working better. If any of you know mailman very well and are willing to coordinate with me the lists, please come forward.
Thanks for your cooperation.
Nagarjuna